Filtering apparatus

ABSTRACT

A filtering apparatus adapted to be connected to a burner apparatus of the furnace type in buildings to remove fly ash, smoke and other contaminate particles from the flue gases or discharge gases therefrom. It includes three stages of filtration the first being a cyclone type separator and the second and third stages being mechanical filters. An exhaust or blower assembly is mounted on the casing to draw gases through the filtering apparatus from the chimney. Operation of the same is made automatic by a temperature sensor in the filtering apparatus which is connected to the chimney by means of transverse duct work. An air inlet is provided in the transverse duct work to draw in ambient air along with the gases for the purposes of cooling the same as they pass through the filtering apparatus.

[ 1 Feb. 20, 1973' [54] FILTERING APPARATUS [75] Inventors: Lawrence 0.Doyle, Jr., Wayzata; llarlen D. Meek, Anoka, both of Minn.

[73] Assignee: Anti-Pollution Devices, lnc., Hopkins, Minn.

22 Filed: Sept. 11, 1970 211 Appl. No.: 71,561

[56] References Cited UNITED STATES PATENTS 2,143,569 1/1939 Nessell..55/217 2,171,248 8/1939 Van Berkel ..55/233 3,240,000 3/1966 Hayes eta1. .,..55/337 3,395,512 8/1968 Finney, Jr. et al ..55/97 3,425,1922/1969 Davis 3,510,904 5/1970 Lagerstrom ..55/217 PrimaryExaminer-Bernard Nozick Attorney--Schroeder, Siegfried & Ryan [5 7ABSTRACT A filtering apparatus adapted to be connected to a burnerapparatus of the furnace type in buildings to remove fly ash, smoke andother contaminate particles from the flue gases or discharge gasestherefrom. It includes three stages of filtration the first being acyclone type separator and the second and third stages being mechanicalfilters. An exhaust or blower assembly is mounted on the casing to drawgases through the filtering apparatus from the chimney. Operation of thesame is made automatic by a'temperature sensor in the filteringapparatus which is connected to the chimney by means of transverse ductwork. An air inlet is provided in the transverse duct work to draw inambient air along with the gases for the purposes of cooling the same asthey pass through the filtering apparatus.

6 Claims, 4 Drawing Figures /5 u u 32 li i" 33 PATENIEDHBZOIW INVENTORLawrence 0. Doyle Jr.

Harlan 0. Meek FILTERING APPARATUS Our invention relates to a filteringapparatus and more particularly to an improved filtering apparatus to beused as an anti-pollution device in connection with filtering exhaustgases from chimneys of furnace type burners.

Filtration devices and filters are well known and in use and take avariety of forms depending upon the application of the same. Similarlystack or chimney filtration is known and complicated filtrationapparatus including scrubbers are employed to eliminate fly ash andsmoke discharge from the same. Incineration of the high temperature typehas been employed to eliminate the problems of pollution caused by smokedischarge and ash discharge from chimneys. Present day anti-pollutionlaws are such that in most communities, small commercial establishments,hotels and apartment buildings which utilize burners to eliminaterubbish are faced with the problem of burner shutdown because ofimproper cleaning apparatus associated with the burners to eliminate thesmoke and ash discharge into the atmosphere. This is particularly truein connection with burner type apparatus employed in apartment buildingsand hotels and other large occupancy type structures. Many suchbusinesses and motels are faced with the problem of handling of rubbishapart from burning since their burning apparatus does not meetanti-pollution laws. Expensive filtration and high temperatureincineration is not practical for such installation.

The present invention is directed to a simplified filtering apparatus orfiltration apparatus which may be positioned at any location inconnection with such businesses or buildings and tied to the exhaustpipes or chimneys of the burners such as to receive the exhaust gases ofthe same and to remove fly ash, smoke and other pollutants from beingdischarged to the atmosphere. This will permit such businesses to complywith anti-pollution laws and does not require expensive remodeling orinstallation of different types burning equipment.

The improved filtration apparatus includes a casing or housing having aplurality of sections therein defined by baffies positioned within thehousing. In the lower most of the section is positioned a cyclone typeseparator with a clean-out at the base of the same and above the cyclonetype separator is positioned two stages of filtration which areconnected in series with the output of the cyclone to remove allcontaminates from the air before discharging the exhaust gases toatmosphere. Each filtration stage is removable for cleaning and thefirst stage adjacent the cyclone is a wire mesh filter which takes outlarge particles not removed by the cyclone. The second or last stage offiltration filters out smoke and other particles down to 1 micron insize and lower permitting the filtration apparatus to dischargepollution free air. Air is drawn through the cyclone and filteringapparatus by an exhaust fan positioned on top of the housing which isconnected to the casing to draw air therefrom and to exhaust it toatmosphere. The filtration apparatus includes a transition or connectingapparatus adapted to be connected to a chimney and directing exhaustgases therefrom to the input of the cyclone in a conventional manner. Anadjustable louver or opening is positioned therein to permit theintroduction of ambient air for the purpose of cooling the exhaust gasesbefore filtration to protect the filtering apparatus. The improvedfiltering apparatus is made automatic by a temperature sensor positionedwithin the casing and operating a switch in circuit with the electricmotor driving the exhaust blower to start the same when ambienttemperature within the casing rises to a predetermined point indicatingburning at a burning apparatus and increased temperature of exhaust gasin the chimney. When the burner is shut down, absence of the exhaust gasor temperature will permit shutdown of the blower. The casing includespanel sections which open to remove the filtration apparatus forservicing, that is cleaning and repair where necessary.

It is therefore the principal object of this invention to provide animproved filtration apparatus particularly adapted for use in connectionwith exhaust gases from burners in commercial installations andapartment buildings.

Another object of this invention is to provide a filtration apparatus ofthis type which incorporates three stages of filtering to remove allcontaminates from the exhaust gases of the burner.

A further object of this invention is to provide a filtration apparatusof this type which is automatically operated by burning in a burningapparatus and a rise in temperature in the apparatus with the presenceof exhaust fumes therefrom.

A still further object of this invention is to provide in a filtrationapparatus of this type a provision for controlling the temperature ofthe exhaust gases by introduction of ambient air thereto.

Another object of this invention is to provide a filtration apparatuswhich is low in cost and easy to service and maintain.

These and other objects of this invention will become apparent from areading of the attached description together with the drawings wherein:

FIG. 1 is a schematic view of the filter apparatus shown in connectionwith a chimney and the transition duct work connected therebetween,

FIG. 2 is a perspective view of the improved filtering apparatus,

FIG. 3 is a sectional view of the filtering apparatus of FIG. 2 takenalong the lines 3--3 therein, and

FIG. 4 is a schematic electrical circuit for the filtering apparatus.

Our improved filtering apparatus is shown schematically in FIG. 1 asconnected to a chimney indicated at 10 at a building site or locationwhich is discharging gas, smoke and fly ash from a burner typeapparatus,

located within a building. The improved filtering apparatus is indicatedgenerally at 15 and is connected to the chimney by means of transition,piping or conduit indicated generally at 20. The filtering device 15 iscomprised of a casing or housing 30 which is generally rectangular incross section and includes a plurality of internal baffle members 32, 33and 34 dividing the casing internally into a plurality of compartments.As will be hereinafter indicated, the baffles have varying types ofapertures therethrough providing communication between the compartmentswithin the casing. At the base of a case and defined by the baffie 34and the bottom thereof is a clean-out section in which is positioned aclean-out drawer 35 with a front panel 36 providing access thereto.Positioned between the baffle 33 and 34 is a cyclone type separatorformed of an outer cylindrical member 40 and a smaller and concentricinner cylindrical member 42, the outer cylindrical member 40 beingsealed at its upper extremity by the baffle 33 and being opened at itslower extremity communicating with an opening in the baffle 34 allowingparticles to drop into the clean-out drawer 35. The outer cylindricalmember has a tangential intake duct 46 attached thereto and the innercylindrical member is open at both extremities being connected to thebaffle 33 to provide the outlet or discharge from the cyclone separatorinto the compartment formed between the baffles 32, 33. Positioned inthis compartment is a wire mesh filter indicated generally at 50 whichis adapted to remove large particles not separated by the cycloneseparator. This compartment is accessible by means of a pivoted panel ordoor 52 in the front of the case providing access thereto to permitremoval of the filter for cleaning purposes.

Positioned between the baffle 32 and the top of the case which is closedis a compartment in which is positioned a large Flanders type filter,indicated generally at 60, the same being mounted on the baffle 32 whichhas a large aperture therein permitting communication between the filter50 and the filter 60. This compartment also has a pivoted door 62 in thefront of the same permitting access to the filter 60 for maintenance andcleaning purposes. On top of the casing or housing and communicatingtherewith by means of an aperture (not shown) in the top of the casingis a blower housing 70 having a blower drum type fan 72 positionedtherein to draw air through the casing. The blower housing 70 has atangential discharge duct 75 connected thereto with pressure typelouvers 76 positioned in the end of the same. An electric motor 80 ismounted on the top of the cabinet and its output shaft 82 is connectedto the drum 72 of the'blower to rotate the same. The electric motor hasa suitable starter control 85 including a control relay 86 (see FIG. 4)by means of which it may be operated from a remote switch 89 positionedin the inlet duct 46 to the cyclone. The switch 89 is operated from atemperature sensing element 88 positioned therein with the switch beingconnected in series circuit to the starter coil or relay 86 to connectthe same to a source of electric power as evidenced by cable 87 foroperating the electric motor and hence the exhaust fan uponpredetermined temperature conditions at the inlet to the centrifugal orcyclone separator.

To improve the operation of the filtering device, the transition pipingor conduit connecting the filtering device to the chimney includes anadjustable aperture 100 which may be adjusted in size by means of anadjustable plate 102 to vary the size of the opening therein. Thisopening provides for the introduction of ambient air into the transitionduct work to cool the flue gas as they enter the filtering apparatus.The size of :the opening will normally be adjusted for normal burningtemperatures of the flue gases and for normal cooling of the same toprotect the filtering apparatus. If desired, the opening can includepressure responsive counterbalanced louvers which open with operation ofthe exhaust blower. Such an opening will normally be located adjacentthe end of the chimney for efficient cooling.

A fail safe structure is also included in the transition duct work 20above the end of the chimney which will become operative uponoverheating of the duct work, or upon malfunction of the filteringapparatus, such as by electric power failure. This structure includes apair of adjustable dampers 110 operated by volatile fill actuators 112.The dampers are normally closed with operation of the filteringapparatus during burning and shutdown. However, in the event ofmalfunction of the filtering apparatus, as by power failure, duringburning an increase in temperature of flue gas at the end of the chimneyand in the duct work above a predetermined level will cause the dampersto open and the flue gases to be vented to atmosphereunfiltered as asafety measure. However, a protective screen 115 is located above thedamper opening in the duct work to prevent the escape of large pieces offly ash. 7

In the operation of our improved filtering device the exhaust gases fromthe chimney with fly ash and other solids and smoke are drawn into thefiltering apparatus through operation of the blower. The inlet to thecyclone will direct the exhaust gases in a spiraling path through. thecyclone and along the inner surface of the outer cylindrical member 40toward the open bottom extremity of the inner cylindrical member 42which is spaced from the baffle 34 and the end of the outer cylindricalmember 40 by a predetermined distance. The spiraling gases will havelarger ash particles and solids filtered out through the operation ofcentrifugal force and the gases will be drawn into the inner cylindricalmember 42 and directed through the filters 50 and in series with oneanother and through the blower housing to be discharged through thelouver discharge extremity of the same. As the burner apparatusassociated with the chimney is placed in operation, a rise intemperature of the exhaust gases emanating therefrom will be directedinto the transition member and through the same into the area of thetemperature sensing element 88 or switch which will turn the blower onand cause a vacuum to be placed on the transition member and the chimneydrawing the exhaust gases through the filtering apparatus. Thetransition, conduit or piping includes the adjustable aperture 100,therein by means of which outside or ambient air may be also drawn intothe duct work and through the filtering apparatus when the blower is inoperation. This lower temperature air will tend to cool the exhaustgases permitting the filtering apparatus to operate at a lowertemperature and prevent destruction of the filtering materials. Thisaperture is adjustable by means of plate 102 and is manually set for thenormal temperature operating conditions of the filtering device and thegaseous discharge from the chimney with which it is associated. Wheredesired, the same may be connected through a temperature sensing controlto allow the aperture to be opened greater amounts with increasedtemperature conditions in the burning apparatus. With the operation ofthe filtering device, blower energization or rotation will continueuntil burning is ceased in the burning apparatus and the temperature ofthe air moving through the transition section and into the filteringapparatus is lowered in temperature to a predetermined point which willallow the switching device to open and de-energize the blower motor.Thus the operation of the filtering device is automatic with burningoperation. Periodic maintenance or clean-out of the filters 50 and 60will be conducted to insure an efficient and maximum of filtrationtherefrom. The filter 50 of a conventional wire mesh type and the filter60 is of the type shown in the U.S. Pat. No. 2,952,333 to L. Bush datedSept. 13, 1960 and entitled Filters. Periodic cleaning of the filterswill be required, as well as the clean-out of the particles deposited inthe cyclone tray to condition the filtering apparatus for continuousoperation.

A safety device in the form of heat motor actuated dampers are includedin the duct work above the chimney to open the same in the event ofmalfunction of the filtering apparatus.

The improved filtering apparatus permits a connection with conventionalburning apparatus presently existing in many commercial establishmentsand in apartment buildings which are not now in operation because ofsmoke discharge therefrom. This simplified filtering apparatus willinsure removal of all fly ash particles and smoke with the discharge ofclean heated air from the burner or stack at the outlet of the blower.The operation of the same is automatic with a rise in temperature of theair in the transition duct between the chimney and the filteringapparatus to turn the blower on and filter out of the flue gases allcontaminates.

In considering this invention it should be remembered that the presentdisclosure is illustrative only and the scope of the invention should bedetermined by the appended claims.

What is claimed is:

l. A filtering device adapted to be connected to a chimney of a furnacetype apparatus comprising, a casing, a cyclone type separator positionedin a base portion of the casing, said cyclone type separator beingformed by a first cylindrical member positioned in the lower portion ofthe casing with a second smaller diameter cylindrical member positionedin said lower portion of the casing and concentric therewith with thesmaller cylindrical member extending short of the length of the largercylindrical member and with an air inlet pipe connected tangentially tothe larger cylindrical member to direct airflow into the casing to theseparator and with an outlet therefrom being connected to the innercylindrical member, a pair of filter members positioned in said casingabove the cyclone type separator with each filter member beingseparately removable from the casing for cleaning purposes with thefilters being positioned at the outlet of the cyclone separator, anexhaust fan including a blower member connected to the casing and havingan air inlet connected to an outlet of said casing beyond said filtermembers and said cyclone with an electric motor drivingly connectedthereto for operating the same, said exhaust fan having an outlet remotefrom said casing, a temperature sensing switch and an electric circuitadapted to be connected to a source of electric power and through theswitch to the electric motor of said blower member, said temperaturesensing switch being responsive to the rise and fall of temperaturewithin the casing above a predetermined temperature and operative toturn on and off respectively said electric motor to operate said exhaustfan above the predetermined temperature transition means connected tothe casing at the inlet to the cyclone and adapted to be connected to achimney, said transition means including a duct work having an air inletpassage therein with an adjustable louver to vary the size of the inletair passage and the amount of atmospheric air outside of the duct workbeing drawn into the casing to cool the exhaust gases from said chimney,and including heat motor actuated dampers positioned in the transitionmeans acijacent the chimney and operative to open the transition meanswith a rise in temperature of exhaust gases from the chimney above apredetermined temperature.

2. The filtering device of claim 1 in which the casing includes aplurality of baffle sections intermediate the extent of the samedefining sections of the casing with apertures through the baffles todefine fiow passages therein between and with the cyclone separator andthe plurality of stages of filtration positioned respectively in thesections defined by the baffie.

3. The filtering device of claim 1 in which the casing includes aplurality of access doors which may be opened to expose the filtrationpositioned in certain of said sections in the casing.

4. The filtering device of claim 1 in which the lower most sectiondefined by one of the baffles in the casing is positioned beneath thecyclone type separator and includes a clean-out tray receiving dustparticles from the cyclone.

5. A filtering device adapted to be connected to a chimney of a furnacetype apparatus comprising, a casing, a cyclone type separator positionedin a base portion of the casing, said cyclone type separator beingformed by a first cylindrical member positioned in the lower portion ofthe casing with a second smaller diameter cylindrical member positionedin said lower portion of the casing and concentric therewith with thesmaller cylindrical member extending short of the length of the largercylindrical member and with an air inlet pipe connected tangentially tothe larger cylindrical member to direct airflow into the casing to theseparator and with the outlet therefrom being connected to the innercylindrical member, a pair of filter members positioned in said casingabove the cyclone type separator with each filter member beingseparately removable from the casing for cleaning purposes with thefilters being positioned at the outlet of the cyclone separator, anexhaust fan including a blower member connected to the casing and havingan air inlet connected to an outlet of said casing beyond said filtermembers and said cyclone with an electric motor drivingly connectedthereto for operating the same, said exhaust fan having an outlet remotefrom said casing, a temperature sensing switch and an electric circuitadapted to be connected to a source of electric power and through theswitch to the electric motor of said blower member, said temperaturesensing switch being responsive to the rise and fall of temperaturewithin the casing above a predetermined temperature and operative toturn on and off respectively said electric motor to operate said exhaustfan above the predetermined temperature transition means connected tothe casing at the inlet to the cyclone and adapted to be connected to achimney, said transition means including a duct work having an air inletpassage therein with an adjustable louver to vary the size of the inletair passage and the amount of atmospheric air outside of the duct workbeing drawn into the casing to cool the exhaust gases from said chimney.

6. The filtering device of claim and including an additional passagemeans communicating with the chimney and including a heat motor operateddamper positioned adjacent said transition means and responsive to risea temperature of the exhaust gases from the chim- 5 ney above apredetermined temperature to open said damper and bypass said transitionmeans.

1. A filtering device adapted to be connected to a chimney of a furnace type apparatus comprising, a casing, a cyclone type separator positioned in a base portion of the casing, said cyclone type separator being formed by a first cylindrical member positioned in the lower portion of the casing with a second smaller diameter cylindrical member positioned in said lower portion of the casing and concentric therewith with the smaller cylindrical member extending short of the length of the larger cylindrical member and with an air inlet pipe connected tangentially to the larger cylindrical member to direct airflow into the casing to the separator and with an outlet therefrom being connected to the inner cylindrical member, a pair of filter members positioned in said casing above the cyclone type separator with each filter member being separately removable from the casing for cleaning purposes with the filters being positioned at the outlet of the cyclone separator, an exhaust fan including a blower member connected to the casing and having an air inlet connected to an outlet of said casing beyond said filter members and said cyclone with an electric motor drivingly connected thereto for operating the same, said exhaust fan having an outlet remote from said casing, a temperature sensing switch and an electric circuit adapted to be connected to a source of electric power and through the switch to the electric motor of said blower member, said temperature sensing switch being responsive to the rise and fall of temperature within the casing above a predetermined temperature and operative to turn on and off respectively said electric motor to operate said exhaust fan above the predetermined temperature transition means connected to the casing at the inlet to the cyclone and adapted to be connected to a chimney, said transition means including a duct work having an air inlet passage therein with an adjustable louver to vary the size of the inlet air passage and the amount of atmospheric air outside of the duct work being drawn into the casing to cool the exhaust gases from said chimney, and including heat motor actuated dampers positioned in the transition means adjacent the chimney and operative to open the transition means with a rise in temperature of exhaust gases from the chimney above a predetermined temperature.
 1. A filtering device adapted to be connected to a chimney of a furnace type apparatus comprising, a casing, a cyclone type separator positioned in a base portion of the casing, said cyclone type separator being formed by a first cylindrical member positioned in the lower portion of the casing with a second smaller diameter cylindrical member positioned in said lower portion of the casing and concentric therewith with the smaller cylindrical member extending short of the length of the larger cylindrical member and with an air inlet pipe connected tangentially to the larger cylindrical member to direct airflow into the casing to the separator and with an outlet therefrom being connected to the inner cylindrical member, a pair of filter members positioned in said casing above the cyclone type separator with each filter member being separately removable from the casing for cleaning purposes with the filters being positioned at the outlet of the cyclone separator, an exhaust fan including a blower member connected to the casing and having an air inlet connected to an outlet of said casing beyond said filter members and said cyclone with an electric motor drivingly connected thereto for operating the same, said exhaust fan having an outlet remote from said casing, a temperature sensing switch and an electric circuit adapted to be connected to a source of electric power and through the switch to the electric motor of said blower member, said temperature sensing switch being responsive to the rise and fall of temperature within the casing above a predetermined temperature and operative to turn on and off respectively said electric motor to operate said exhaust fan above the predetermined temperature transition means connected to the casing at the inlet to the cyclone and adapted to be connected to a chimney, said transition means including a duct work having an air inlet passage therein with an adjustable louver to vary the size of the inlet air passage and the amount of atmospheric air outside of the duct work being drawn into the casing to cool the exhaust gases from said chimney, and including heat motor actuated dampers positioned in the transition means adjacent the chimney and operative to open the transition means with a rise in temperature of exhaust gases from the chimney above a predetermined temperature.
 2. The filtering device of claim 1 in which the casing includes a plurality of baffle sections intermediate the extent of the same defining sections of the casing with apertures through the baffles to define flow passages therein between and with the cyclone separator and the plurality of stages of filtration positioned respectively in the sections defined by the baffle.
 3. The filtering device of claim 1 in which the casing includes a plurality of access doors which may be opened to expose the filtration positioned in certain of said sections in the casing.
 4. The filtering device of claim 1 in which the lower most section defined by one of the baffles in the casing is positioned beneath the cyclone type separator and includes a clean-out tray receiving dust particles from the cyclone.
 5. A filtering device adapted to be connected to a chimney of a furnace type apparatus comprising, a casing, a cyclone type separator positioned in a base portion of the casing, said cyclone type separator being formed by a first cylindrical memBer positioned in the lower portion of the casing with a second smaller diameter cylindrical member positioned in said lower portion of the casing and concentric therewith with the smaller cylindrical member extending short of the length of the larger cylindrical member and with an air inlet pipe connected tangentially to the larger cylindrical member to direct airflow into the casing to the separator and with the outlet therefrom being connected to the inner cylindrical member, a pair of filter members positioned in said casing above the cyclone type separator with each filter member being separately removable from the casing for cleaning purposes with the filters being positioned at the outlet of the cyclone separator, an exhaust fan including a blower member connected to the casing and having an air inlet connected to an outlet of said casing beyond said filter members and said cyclone with an electric motor drivingly connected thereto for operating the same, said exhaust fan having an outlet remote from said casing, a temperature sensing switch and an electric circuit adapted to be connected to a source of electric power and through the switch to the electric motor of said blower member, said temperature sensing switch being responsive to the rise and fall of temperature within the casing above a predetermined temperature and operative to turn on and off respectively said electric motor to operate said exhaust fan above the predetermined temperature transition means connected to the casing at the inlet to the cyclone and adapted to be connected to a chimney, said transition means including a duct work having an air inlet passage therein with an adjustable louver to vary the size of the inlet air passage and the amount of atmospheric air outside of the duct work being drawn into the casing to cool the exhaust gases from said chimney. 